intercooler should work in any browser that your chosen version of jquery or zepto works in.
If you want to see if a particular browser is compatible with a particular version of intercooler + (jquery || zepto), the unit tests are linked off the release page:
This will run all tests for intercooler 1.2.1 using jQuery3 as the underlying library. Be sure to let the window retain focus or a few tests will fail.
See: https://github.com/stimulusjs/stimulus/blob/master/INSTALLIN...